TheSupport@KMI wrote:And similar to Danimal's solution, if people don't want to be running computers without ground they can get a USB isolator, which is basically just a ground lift for a USB signal. Put it between the computer and QuNexus and the noise goes away.

Even with the LEDs off I do get some CV noise (rising and falling along with the CV signals) when the instrument is not producing loud signal. I applied a noise gate to hide this, but an isolator is a better option.

Incidentally I now have the QuNexus setup in the Logic environment such that anything sent to port 2 (midi) is also sent to port 1 (LEDs) and port 3 (CV). This allows one midi track to contain the notes, expression (mod, velocity, etc), and also light up the keyboard as intended.